Circuit-breaker for telephone ljnes



(No Model.)

G. H. GLASS & W. CLARK.

CIRCUIT BREAKER FOR TELEPHONE LINES.

No. 340,912. Patented Apr. 2'7, 1886 r y M m m m M W A 1 UNITED STATESPATENT OFFICE.

GEORGE H. GLASS AND lVrklflTliP CLARK, OF RALEIGH, FORTH CAROLINA.

CIRCUIT-BREAKER FOR TELEPHONE LlNES.

SPECIFICATION forming part oi Letters Patent -"\To. 340,912,6iated April2'7, 1886.

Application filed June 23, 1835.

To aZZ whom it may concern.-

Be it known that we, GEORGE H. GLASS and XVALTER CLARK, of Raleigh, inthe county of \Vake and State of North Carolina, have in- 5 ventedcertain new and useful Improvements in Circuit-Breakers for TelephoneLines; and we do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to re which it pertains to make and use the same.

Our invention has reference to circuit-break ing devices designed forsignaling a subscriber from the main office or exchange; and it consistsin the improvements hereinafter fully set 1 forth and explained.

In the accompanying drawing, forming part of this specification, thefigure represents a diagrammatic View illustrating the manner ofoperatingtheimproved pole-changer, which latter is illustrated insection.

In a suitable case, A, is located an electro magnet, B, consisting of asuitable core, the coils being included in the circuit of a localbattery, represented at a, the wires 0 d of which lead to binding-screwsof, from whence wires 0 f lead to the coils of the electro-magnet B;also, within the case A, at each side of the same, is located,respectively, a bracket, 0 C, each of which terminates in verticalportion,

0 horizontally perforated, for the passage of a binding-screw, g g, aportion of which projects to form contact.

D refers to an armature, which is pivotally suspended at its upper end,and is maintained 5 in a vertical position by a weight or pendulum, h,adjustably secured on an extension de pending from the armature D. Aspring, t, holds the armature in positive contact with the projectingportion of the screw r "ii ires o ji't, leading from the binding-postscf, respectively, contact with the pivot of the armature and with thebinding-screw g.

The main or line wire receives its current from the main batteries, andis designated by E, one pole of which is grounded, while the Serial Xe,169,505. (X0 model.)

makes connection with the armature D by means of wire 0, while it alsoconnects with the line plate or section F.

in practice the local circuit, represented by the wires leading from thebattery a through the coils of the magnet B, is closed, and the magnetrepresented by B magnetized, thus attracting the armature D, which, uponcontacting with the screws 9, creates a short-circuit through the wiresj and 7.: and armature, thus demagnetizing the magnet B, and enablingthe spring 2' to draw the armature away from the magnet, and causing thearmature to contact with the screw 9. The latter contact completes themain circuit.

The subscriber having made connection with the plate or section includedin the main circuit, and also grounded his instrument, the re peatedcontacting and receding movement of the armature D results in the maincircuit, in which the subscribcfls signal or call bell is l0- cated,being rapidly broken, but not to such an extent as to inter-{ere withthe clear and loud ringing of the bell.

By the construction of the instrument, as herein described, thesubscribers circuit is only broken on one side of the armature, whereasin many of the forms of instruments heretofore used the circuit isbroken on both sides, so as to result in the interruptions being toorapid, thus interfering with the clear and loud ringing of thesubscribers bell.

XVe are aware that in electric bells it has been common to employ thebell-armature to shortcircuit the current of the operating-magnet, inorder to permit the retraction of the bellarmature.

We claim- 1. The combination, in a telephone-call system,of the mainline, a circuit-breaker provided with a single magnet, the coils ofwhich are always in the local circuit, and ashort-circuit derived fromsaid local circuit, an armature adapted to be attracted by said magnetand retracted therefrom by a spring, and contacts for said main andshort circuits on the oppomovement of the armature alternately breaksthe main and short circuits, substantially as set forth.

2. The combination, in a telephone-call system, of a circuit-breakingdevice consisting of a single magnet, B,wires e f, included in the localcircuit and forming the coils of said magnet, an armature, D, Wires j k,leading from said local circuit and connecting, respectively, witharmature D and with a contact, 9', a contact, main battery lineconnectingtherewith,

'and line-wire connecting with said armature,

whereby said main circuit is broken only on one side of said magnet,substantially as set forth.

In testimony whereof we have signed this I 5 specification in thepresence of two subscribing witnesses.

G. H. GLASS. WALTER CLARK.

Witnesses:

A. W. SHAFFER, D. REID UPOHURCH.

